Sarcoidosis
Sarcoidosis is a condition where there is development of fleshy swellings, called granulomas, in lymph nodes and in other tissues of the body such as the lungs and the skin. The word granuloma is derived from granulation tissue, the tissue containing blood vessels and connecting cells which is produced as part of the process of wound healing. A granuloma is something that develops in response to chronic inflammation, and those that occur in sarcoidosis resemble those that occur in tuberculosis. There is increasing evidence that this is in fact an infectious disease rather than primarily autoimmune. The most common site of involvement is in the lymph nodes in the chest, often found incidentally on a routine chest X-ray. Skin involvement frequently produces painful red swellings called erythema nodosum on the front of the shins; eye involvement causes uveitis or iritis (described in the section on eye disorders) while involvement of the heart, which is rare, can cause problems with the rate and rhythm of the heart beat or impaired contraction. In many cases the disorder is asymptomatic, benign and self-limiting. In others there may be generalised symptoms of muscle aches and pains, fever and weight loss together with the specific symptoms of cough, shortness of breath and eye pain. Diagnosis may be aided by biopsy of a granuloma, or by a procedure called a Kveim test, where a suspension of spleen cells from an affected person are injected into the skin; subsequent biopsy of the site after a number of weeks will show the development of granulomas in those who have sarcoidosis.
Most cases will resolve without treatment, though some may require treatment with steroids or other agents to suppress the immune response.
|
